Device for treating a product in continuous movement, such as a tube or wire



1966 G. J. P. GUEUGNIER 3,267,253 DEVICE FOR TREATING A PRODUCT IN CONTINUOUS MOVEMENT, SUCH AS A TUBE OR WIRE Filed June 4, 1963 lo o I;

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INVENTOR GUY JEAN PIERRE GUEUGNIER M MW ATTORNEYS 1 3,267,253 Ce Patented August 16, 1966 3,267 253 DEVICE FOR TREATING A PRODUCT IN CON- TINUOUS MOVEMENT, SUCH AS A TUBE OR WIRE Guy Jean Pierre Gueugnier, Paris, France, asslgnor, by

mesne assignments, to Friedrich Kocks Firma, Dusseldorf, Germany Filed June 4, 1963, Ser. No. 285,343 6 Claims. (Cl. 219-155) The present invention relates to a device for the heating by the Joule effect of a product in continuous movement, such as a tube or a wire of electrically-conducting material, and in particular a device for heating a welded metal tube during the course of its manufacture.

The device according to the invention comprises at least two successive units each comprising two oppositelyfacing rollers, between the grooves of which the product passes, at least one of the rollers of one unit being of electrically-conducting material and being supplied with current from a bath of mercury, either directly or through the intermediary of the shaft on which it is mounted. These rollers preferably have their axes vertical.

Each group of two heating units is supplied at an appropriate voltage, the arrangement of the groups being effected in such manner as to be adapted to the type of electric current which is available. For example, if the device is supplied with three-phase current, it may comprise three successive heating zones, or a multiple of three corresponding to each phase of the current. However, on the downstream side of the device with respect to the direction of movement of the product, the latter may be sufficiently hot for one or more of the roller units to be replaced by one or more heating shoes 'which are simpler to manufacture and to install.

In the case where there is only a single heating roller in each unit, the successive heating rollers will preferably be arranged on each side of the product, so as to obtain uniform heating by the alternating effect of the heating rollers.

By reason of the rotation of the rollers during the course of the passage of the product, hearings or rings are currently utilized, and it is then advantageous to arrange matters so that the electric current does not pass through them nor along their axes. In both cases, in fact, the bearings or the rings would be rapidly damaged.

To this end, in accordance with one form of embodiment, the shaft of conducting material which carries the roller is suspended at its upper portion from a frame through the intermediary of bearings, and its lower portion is continuously immersed in a bath of mercury.

According to an alternative form of construction, the shaft carrying the roller at its upper portion is supported at its lower portion by a frame, through the intermediary of bearings, and the mercury bath is arranged between the roller and the frame, the roller being provided with at least one element which is continuously immersed in the bath of mercury.

In accordance with another alternative form, the roller is carried by a shaft fixed in rotation to the intermediary of a bearing, and comprises at least one element which is continuously immersed in the bath of mercury arranged under the roller.

A particularly advantageous feature of the invention, in the case where the rollers of the same unit are both heating rollers, consist in supplying them with current by means of a common bath of mercury.

In accordance with a further particular feature of the invention which may be chosen for preference, the mercury is contained in a tank made of a material which is not attacked by mercury, and the input of the current is insured by a conducting plate immersed in the mercury.

Other particular features which also form part of the invention will become apparent during the course of the description which follows below, reference being made to the accompanying drawings which are especially given by way of example; in these drawings:

FIG. 1 is a diagrammatic view of a heating device in accordance with the invention;

FIG. 2 is a diagrammatic view in partial cross-section, of a heating unit comprising two oppositely-facing rollers, of which one is a heating roller;

FIG. 3 is a view similar to FIG. 2, but showing the case where both the rollers are heating rollers;

FIGS. 4 and 5 are alternative forms of construction of the device of FIG. 3;

FIG. 6 is a diagrammatic view of a heating shoe.

In FIG. 1, there has been shown diagrammatically a device for heating "by the Joule effect, according to the invention, a product of an electrically-conducting material such as a tube 1 which is in continuous movementf In this example, the device comprises successively, in the I direction of movement of the tube, four units 2, 2a, 2b,

20, each With two oppositely-facing rollers, an upper heating shoe 3 and a lower heating shoe 4. The device is supplied with three-phase alternating current.

A form of embodiment of a unit with two rollers 5 and 6 is shown in FIG. 2. These rollers are of the semicircular groove vertical axis type, and are made of electrically-conducting material. They are intended to co-operate with the elongated element 1 with a circular section, of electrically-conducting material, such as a welded metallic tube. This tube moves in a direction perpendicular to the plane of the figure. Each roller is carried by a shaft 7 or 7' so as to be able to rotate about a vertical axis.

In the form of embodiment shown in this figure, the shafts are suspended from frames 8 and 9 respectively, and bearings 10 are housed between each shaft and the corresponding frame. These frames are mounted in horiz-ontal slides 11 of a fixed support, while means are provided to permit the frames to move in the slides in order to adjust the distance between the rollers.

The roller 5 is a heating roller while the roller 6 is a retaining roller. According to the invention, the shaft 7 of the roller 5 is extended at its lower extremity under the roller by a widened portion 12, which is continually immersed in a mercury bath 13. The mercury is contained in a tank 14 of electrically-conducting material :such as copper, and the electric current is led directly to the tank by a conductor 15.

It can thus be seen that the current passes into the tank 14 to the mercury 13 and from there to the shaft 7 and the roller 5, and then into the tube 1 from which it passes out through a further unit with two rollers either on the downstream or the upstream side. The tube 1 is then heated by the Joule effect by virtue of the passage of a current distributed uniformly over one-half of its section. In consequence, it will be preferable to provide in a further heating unit located on the upstream or downstream side, an arrangement permitting the current to be passed through the other half of the section of the tube. This additional unit will thus comprise a heating roller located on the other side of the tube.

In the form of embodiment shown in FIG. 3, the rollers 5a and 6a are also suspended from frames 8 and 9, but they are both heating rollers. To this end, each of the shafts 7a and Ta which carries them is extended at its lower extremity by a portion of larger diameter 12a and 16a respectively. According to a particular feature of the invention, these extensions are continually immersed in mercury contained in a tank 14a, common to the two rollers.

According to a further particular feature of the invention, the tank is of a material which is not attacked by mercury, such as steel, while the current is supplied to the mercury by a conducting plate 17 which is immersed in the mercury.

It can be seen that the current passes simultaneously into the two shafts 7a and 7 'a and into .the rollers 5a and 6a, then into the metal tube 3, substantially along the whole sectionof the tube. The heating of the tube by the Joule effect Will thus be uniform over the Whole section of the tube.

The foregoing forms of construction enable the passage of the current to be kept away from the axis of the bearings which would otherwise be rapidly damaged by induced currents. However, instead of arranging the bearings on one side of the rollers and the current connection on the other side, use may be made of other solutions which also protect the bearings and prevent leakages of current through the frames.

One of these solutions is shown diagrammatically in FIG. 4. The two rollers 5b and 6b, which are both heating rollers, are mounted in the vicinity of the upper extremities of the shafts 7b and Th. The lower extremities of these shafts rotate in bearings 1% carried by frames 8b and 9b, which can slide in the guides 11b.

Between the rollers and the frame is arranged a common tank 14b filled with mercury. If this container is of steel or other material which is not attacked by mercury, the current is led into the mercury by means of a conducting plate 17b.

In addition, the rollers are provided on their lower faces with projecting portions 18 of conducting material which form built-on current collectors by plunging continuously into the mercury of the common container 14b. These extensions may be continuous, in the form of a cylinder, or discontinuous in the form of uniformly spaced apart vertical blades.

In this form of embodiment, there is again obtained a uniform heating of the whole section of the tube 1, without the current passing into the axis of the bearings. It should however be observed that, contrary to the preceding case, the shafts 7b, 7'!) do not require to be of electrically-conducting material, since the transmission of the current can be effected without their intermediary.

FIG. 5 shows a further alternative form of construction, again having two heating rollers 50 and 6c. The latter are not fast for rotation with the shafts 7c and 7'c (as in the previous embodiments) but are mounted on the latter through the intermediary of bearings 100. The rollers may be mounted at the lower part of the shafts which are then suspended from frames. They may also be carried by the upper portions of the shafts as shown. The shafts are then provided at their upper extremities 'with a sole-plate 19, 19, engaged in a slide 110 of a fixed support in order to permit the adjustment of the distance apart of the rollers.-

A tank 140, for example of steel, is supported between the rollers and the sole-plates of the shafts. It is filled with mercury which receives electric current by means of a conducting plate 170. Each roller is extended under its lower face by one or more current collectors 18c, built on and dipping into the mercury of the bath.

All the advantages mentioned above, namely: heating of the whole section of the tube and protection of the bearings, are also obtained with this form of embodiment.

It will be understood that the various forms of construction which have been described may be given numerous modifications, Without thereby departing from the scope of the present invention. Similarly, it is possible to combine the various particular features in a different way. For example, in the case of FIGS. 3, 4 and 5, it is possible to utilize a conducting tank such as that of FIG. 2. The embodiments of FIGS. 3, 4 and 5 could also be carried into effect with a single heating roller, the other serving simply to support the tube.

Finally, instead of having a mercury container common for both rollers, there could be a separate container for each roller. In the case of FIGS. 2 and 3, instead of extending the shaft of a roller so as to dip into the mercury, it would be possible not to extend it and to effect the current connection by means of built-on current collectors rigidly fixed to the corresponding roller. It is then no longer necessary for the shaft to be of electrically-conducting material.

It should be noted that the devices described must be completed, in particular by a cover 20 preventing impurities such as scale from falling into the mercury bath. This cover must be designed in such manner as to take account of variations in the distance apart of the rollers. This same consideration applies to the passage of the roller shafts through the mercury container.

As previously indicated and as shown by way of example in FIG. 1, the heating device may comprise one or more heating shoes on the downstream side. A shoe of this kind is shown diagrammatically in FIG. 6. The shoe proper 21 has a concave surface in contact with part of the surface of the product 1 and is carried by an arm 22 pivoted about a fixed axis 23. An appropriate means such as a jack 24 pivoted on the arm 22 and being supported on a fixed portion 25, continuously forces the shoe against the product. In the case shown, the shoe heats the product from underneath. This arrangement may eventually be completed by an upper shoe, heating the product from the top.

What I claim is:

1. A device for heating by the Joule effect an alongated electrically-conductive product in continuous movement, comprising: supporting means, at least one frame supported by said supporting means, bearings housed in said frame, a vertical electrically-conductive shaft rotatively mounted in said frame by means of said bearings, said shaft having a projecting portion outside said frame, an electrically-conductive roller secured to said projecting portion of said shaft for engaging said product, a mercury-containing tank arranged beneath said roller, means for leading electric current to the mercury of said mercury-containing tank, and dipping means immersed in the mercury for leading electric current to said roller through said projecting portion of said shaft.

2. A device according to claim 1, wherein said projecting portion of said shaft is the lower end thereof, said roller is carried by said shaft beneath said frame, and said dipping means comprises a projecting member carried by said lower end of said shaft and immersed in the mercuryof said mercury-containing tank.

3. A device according to claim 1, wherein said projecting portion of said shaft is the upper end thereof, said roller is carried by said shaft above said frame, and said tank is arranged between said roller and said frame, and said dipping means comprises at least one projecting member carried directly by said roller and immersed in the mercury of said mercury-containing tank.

4. A device for heating by the Joule effect an elongated electrically-conductive product in continuous movement, comprising: supporting means, at least one frame slidably supported by said supporting means, a vertical shaft rotatively suspended in said frame by means of bearings housed in said frame, said shaft having a lower projecting end, a roller carried by said shaft beneath said frame for engaging said product, a mercury-containing tank arranged beneath said shaft, a projecting member carried by said lower end of said shaft, said projecting member being immersed in the mercury of said mercurycontaining tank, and means for leading electric current to said mercury.

5. A device according to claim 4, wherein said means for leading electric current to the mercury of said mercury-containing tank comprises a conducting plate fed with electric current and dipping into the mercury of said tank.

6. A device according to claim 4, comprising two References Cited by the Examiner UNITED STATES PATENTS Shaw 219-155 Anschutz-Kaempfe 339-118 Alexander et al. 219--155 Pancoast 21959 Sjobring et al. 21984 Sessions 219--59 1/1928 Reniers 219155 2/1935 Sykes 21984 6/1936 Newton 21959 7/1936' Borgadt 21959 6/1941 Bohn 21983 7/1947 Bard 339118 FOREIGN PATENTS 2/ 1912 Germany. 3/1932 Germany.

RICHARD M. VJOOD, Primary Examiner. B. A. STEIN, Assistant Examiner. 

1. A DEVICE FOR HEATING BY THE JOULE EFFECT AN ALONGATED ELECTRICALLY-CONDUCTIVE PRODUCT IN CONTINUOUS MOVEMENT, COMPRISING: SUPPORTING MEANS, AT LEAST ONE FRAME SUPPORTED BY SAID SUPPORTING MEANS, BEARINGS HOUSED IN SAID FRAME, A VERTICAL ELECTRICALLY-CONDUCTIVE SHAFT ROTATIVELY MOUNTED IN SAID FRAME BY MEANS FOR SAID BEARINGS, SAID SHAFT HAVING A PROJECTING PORTION OUTSIDE SAID FRAME, AN ELECTRICALLY-CONDUCTIVE ROLLER SECURED TO SAID PROJECTING PORTION OF SAID SHAFT FOR ENGAGING SAID PRODUCT, A MERCURY-CONTAINING TANK ARRANGED BENEATH SAID ROLLER, MEANS FOR LOADING ELECTRIC CURRENT TO THE MERCURY OF SAID MERCURY-CONTAINING TANK, AND DIPPING MEANS IMMERSED IN THE MERCURY FOR LEADING ELECTRIC CURRENT TO SAID ROLLER THROUGH SAID PROJECTING PORTION OF SAID SHAFT. 